Common law is primarily derived from which of the following sources?

Common law fundamentally originates from judicial decisions and longstanding customs rather than from written statutes or formal legislation. This body of law has developed over centuries through court rulings and the application of legal principles to resolve disputes. When judges interpret laws or rules in the context of specific cases, they often set precedents that guide future decisions. This system relies heavily on the doctrine of stare decisis, where courts are bound to follow earlier decisions in similar cases, fostering consistency and stability in the law.

While constitutional amendments and governing statutes are essential elements of legal systems, they are part of statutory law rather than common law. International treaties also do not contribute to common law, as they are agreements between nations and are distinct from the internal legal frameworks governing a jurisdiction. Therefore, the focus on judicial decisions and ancient customs as the basis of common law makes the selected answer the most accurate choice.